1. Field of the Invention
This invention is directed to a brake tester and particularly is directed to a sensor assembly for mapping the position of a brake shoe and specifically for mapping the contact surface between a brake shoe lining/friction pad and a drum surface.
2. Description of the Prior Art
Numerous brake testers exist within the prior art. Many of these brake testers simply involve a sensor embedded within a brake pad which, when worn away due to progressing pad wear, opens a circuit to produce a signal indicating that the brake pads need replacement.
U.S. Pat. No. 5,632,359 to Camps, et al. discloses a capacitive sensor to detect excessive wear of a brake pad in a disk brake assembly and is incorporated herein by reference. U.S. Pat. No. 4,182981 to Shum, et al.; U.S. Pat. No. 4,924,172 to Holmgren; and U.S. Pat. No. 5,497101 to Fillion, each disclose capacitive distance measuring devices in non brake related arts and are incorporated herein by reference. Various other non relevant brake testers exist in the prior art.
Heretofore, the brake testing art has not disclosed or suggested a testing device to map the position of a brake shoe and the contact surface of the brake lining.